CN113223912A - Low work function material modified carbon nano material functionalized needle tip and preparation method thereof - Google Patents
Low work function material modified carbon nano material functionalized needle tip and preparation method thereof Download PDFInfo
- Publication number
- CN113223912A CN113223912A CN202110328379.9A CN202110328379A CN113223912A CN 113223912 A CN113223912 A CN 113223912A CN 202110328379 A CN202110328379 A CN 202110328379A CN 113223912 A CN113223912 A CN 113223912A
- Authority
- CN
- China
- Prior art keywords
- needle
- carbon nano
- tip
- work function
- low work
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000463 material Substances 0.000 title claims abstract description 93
- 239000002086 nanomaterial Substances 0.000 title claims abstract description 92
- 238000002360 preparation method Methods 0.000 title claims abstract description 14
- 150000001721 carbon Chemical class 0.000 title claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 194
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 179
- 229910052751 metal Inorganic materials 0.000 claims abstract description 98
- 239000002184 metal Substances 0.000 claims abstract description 98
- 239000002110 nanocone Substances 0.000 claims abstract description 90
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 86
- 239000010937 tungsten Substances 0.000 claims abstract description 85
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims abstract description 84
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000002041 carbon nanotube Substances 0.000 claims abstract description 10
- 229910021393 carbon nanotube Inorganic materials 0.000 claims abstract description 10
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 10
- -1 boride Chemical class 0.000 claims abstract description 9
- 150000001875 compounds Chemical class 0.000 claims abstract description 9
- XMWRBQBLMFGWIX-UHFFFAOYSA-N C60 fullerene Chemical compound C12=C3C(C4=C56)=C7C8=C5C5=C9C%10=C6C6=C4C1=C1C4=C6C6=C%10C%10=C9C9=C%11C5=C8C5=C8C7=C3C3=C7C2=C1C1=C2C4=C6C4=C%10C6=C9C9=C%11C5=C5C8=C3C3=C7C1=C1C2=C4C6=C2C9=C5C3=C12 XMWRBQBLMFGWIX-UHFFFAOYSA-N 0.000 claims abstract description 8
- 229910003472 fullerene Inorganic materials 0.000 claims abstract description 8
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 8
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 7
- 150000004767 nitrides Chemical class 0.000 claims abstract description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 6
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 3
- 229910017052 cobalt Inorganic materials 0.000 claims abstract description 3
- 239000010941 cobalt Substances 0.000 claims abstract description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims abstract description 3
- 229910052742 iron Inorganic materials 0.000 claims abstract description 3
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 3
- 239000010936 titanium Substances 0.000 claims abstract description 3
- 239000000758 substrate Substances 0.000 claims description 44
- 238000000034 method Methods 0.000 claims description 31
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 24
- 229910052710 silicon Inorganic materials 0.000 claims description 24
- 239000010703 silicon Substances 0.000 claims description 24
- 238000010438 heat treatment Methods 0.000 claims description 16
- 239000002904 solvent Substances 0.000 claims description 11
- 239000007788 liquid Substances 0.000 claims description 10
- 229910025794 LaB6 Inorganic materials 0.000 claims description 9
- 238000011049 filling Methods 0.000 claims description 9
- 238000001704 evaporation Methods 0.000 claims description 6
- 229910005093 Ni3C Inorganic materials 0.000 claims description 5
- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Inorganic materials O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 5
- 239000000843 powder Substances 0.000 claims description 5
- 238000009713 electroplating Methods 0.000 claims description 4
- 238000004544 sputter deposition Methods 0.000 claims description 4
- 238000007740 vapor deposition Methods 0.000 claims description 4
- 229910052769 Ytterbium Inorganic materials 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 238000001035 drying Methods 0.000 claims description 2
- 239000000155 melt Substances 0.000 claims description 2
- 238000002156 mixing Methods 0.000 claims description 2
- 238000000967 suction filtration Methods 0.000 claims description 2
- 238000005406 washing Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 2
- 230000005684 electric field Effects 0.000 abstract description 3
- 238000005036 potential barrier Methods 0.000 abstract description 3
- 238000007306 functionalization reaction Methods 0.000 abstract description 2
- 239000007769 metal material Substances 0.000 abstract description 2
- 239000000523 sample Substances 0.000 description 50
- 239000010408 film Substances 0.000 description 25
- RFFLAFLAYFXFSW-UHFFFAOYSA-N 1,2-dichlorobenzene Chemical compound ClC1=CC=CC=C1Cl RFFLAFLAYFXFSW-UHFFFAOYSA-N 0.000 description 18
- 238000000151 deposition Methods 0.000 description 14
- 238000001228 spectrum Methods 0.000 description 14
- 230000005540 biological transmission Effects 0.000 description 13
- 238000001755 magnetron sputter deposition Methods 0.000 description 10
- 239000010409 thin film Substances 0.000 description 10
- 239000006185 dispersion Substances 0.000 description 9
- 238000001000 micrograph Methods 0.000 description 9
- 238000004458 analytical method Methods 0.000 description 8
- 238000013459 approach Methods 0.000 description 8
- 238000000576 coating method Methods 0.000 description 7
- 238000002604 ultrasonography Methods 0.000 description 7
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 6
- DBTMQFKUVICLQN-UHFFFAOYSA-K scandium(3+);triacetate Chemical compound [Sc+3].CC([O-])=O.CC([O-])=O.CC([O-])=O DBTMQFKUVICLQN-UHFFFAOYSA-K 0.000 description 6
- 239000000945 filler Substances 0.000 description 5
- 239000002105 nanoparticle Substances 0.000 description 5
- 239000003153 chemical reaction reagent Substances 0.000 description 4
- 238000005566 electron beam evaporation Methods 0.000 description 4
- 238000010894 electron beam technology Methods 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 150000001247 metal acetylides Chemical class 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- HYXGAEYDKFCVMU-UHFFFAOYSA-N scandium oxide Chemical compound O=[Sc]O[Sc]=O HYXGAEYDKFCVMU-UHFFFAOYSA-N 0.000 description 3
- 238000003917 TEM image Methods 0.000 description 2
- ORILYTVJVMAKLC-UHFFFAOYSA-N adamantane Chemical compound C1C(C2)CC3CC1CC2C3 ORILYTVJVMAKLC-UHFFFAOYSA-N 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 229910001938 gadolinium oxide Inorganic materials 0.000 description 2
- 229940075613 gadolinium oxide Drugs 0.000 description 2
- CMIHHWBVHJVIGI-UHFFFAOYSA-N gadolinium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Gd+3].[Gd+3] CMIHHWBVHJVIGI-UHFFFAOYSA-N 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 238000004611 spectroscopical analysis Methods 0.000 description 2
- 238000009987 spinning Methods 0.000 description 2
- 239000013077 target material Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 241000968352 Scandia <hydrozoan> Species 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000010849 ion bombardment Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 239000002120 nanofilm Substances 0.000 description 1
- 239000002071 nanotube Substances 0.000 description 1
- 239000002070 nanowire Substances 0.000 description 1
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical group O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 description 1
- HJGMWXTVGKLUAQ-UHFFFAOYSA-N oxygen(2-);scandium(3+) Chemical compound [O-2].[O-2].[O-2].[Sc+3].[Sc+3] HJGMWXTVGKLUAQ-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000000935 solvent evaporation Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009210 therapy by ultrasound Methods 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
- H01J1/02—Main electrodes
- H01J1/30—Cold cathodes, e.g. field-emissive cathode
- H01J1/304—Field-emissive cathodes
- H01J1/3042—Field-emissive cathodes microengineered, e.g. Spindt-type
- H01J1/3044—Point emitters
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/02—Details
- H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement, ion-optical arrangement
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/02—General constructional details
- G01R1/06—Measuring leads; Measuring probes
- G01R1/067—Measuring probes
- G01R1/06711—Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
- G01R1/06733—Geometry aspects
- G01R1/0675—Needle-like
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/02—General constructional details
- G01R1/06—Measuring leads; Measuring probes
- G01R1/067—Measuring probes
- G01R1/06711—Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
- G01R1/06733—Geometry aspects
- G01R1/06738—Geometry aspects related to tip portion
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/26—Electron or ion microscopes; Electron or ion diffraction tubes
- H01J37/28—Electron or ion microscopes; Electron or ion diffraction tubes with scanning beams
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes
- H01J9/025—Manufacture of electrodes or electrode systems of cold cathodes of field emission cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes
- H01J9/042—Manufacture, activation of the emissive part
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B1/00—Devices without movable or flexible elements, e.g. microcapillary devices
- B81B1/006—Microdevices formed as a single homogeneous piece, i.e. wherein the mechanical function is obtained by the use of the device, e.g. cutters
- B81B1/008—Microtips
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01Q—SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM]
- G01Q70/00—General aspects of SPM probes, their manufacture or their related instrumentation, insofar as they are not specially adapted to a single SPM technique covered by group G01Q60/00
- G01Q70/08—Probe characteristics
- G01Q70/10—Shape or taper
- G01Q70/12—Nanotube tips
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2201/00—Electrodes common to discharge tubes
- H01J2201/30—Cold cathodes
- H01J2201/304—Field emission cathodes
- H01J2201/30403—Field emission cathodes characterised by the emitter shape
- H01J2201/30407—Microengineered point emitters
- H01J2201/30415—Microengineered point emitters needle shaped
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2201/00—Electrodes common to discharge tubes
- H01J2201/30—Cold cathodes
- H01J2201/304—Field emission cathodes
- H01J2201/30403—Field emission cathodes characterised by the emitter shape
- H01J2201/30426—Coatings on the emitter surface, e.g. with low work function materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2201/00—Electrodes common to discharge tubes
- H01J2201/30—Cold cathodes
- H01J2201/304—Field emission cathodes
- H01J2201/30446—Field emission cathodes characterised by the emitter material
- H01J2201/30453—Carbon types
- H01J2201/30469—Carbon nanotubes (CNTs)
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
- H01J2237/06—Sources
- H01J2237/063—Electron sources
- H01J2237/06325—Cold-cathode sources
- H01J2237/06341—Field emission
Abstract
The invention relates to the field of metal material functionalization, in particular to a carbon nano material functionalized needle tip modified by a low work function material and a preparation method thereof. The carbon nano material functionalized needle tip modified by the low work function material is formed by combining a carbon nano material with a needle tip material through a covalent bond; a low work function material is modified inside or on the outer surface of the carbon nano material; wherein, the needle point is made of metal and is selected from one or more of tungsten, iron, cobalt, nickel and titanium; the carbon nano material is a carbon nano cone or a carbon nano tube, and the orientation of the tip of the carbon nano material is consistent with that of the metal needle tip; the low work function material is one or more selected from metal, metal carbide, metal oxide, boride, nitride and metal fullerene inclusion compound. The carbon nano material functionalized needle tip has a lower electron emission potential barrier, can effectively reduce the electric field intensity required by electron emission, and improves the emission current and the emission efficiency.
Description
Technical Field
The invention relates to the field of metal material functionalization, in particular to a carbon nano material functionalized needle tip modified by a low work function material and a preparation method thereof.
Background
Based on the novel physical and chemical properties of the nano material, the functional needle tip of the nano material has wide application in the fields of electron emission sources, scanning probe microscopes, vacuum electronic devices, biomedicine and the like. The conventional nanometer material functionalized needle tip is used for adhering nanometer materials (comprising nanowires, nanotubes and the like) to the front end of a needle tip substrate by utilizing physical adsorption force[1]And carbon or platinum material is deposited between the nanometer material and the needle tip substrate for fixing[2-4]. The carbon nano tube functionalized needle tip is prepared by the method and is used for the research of field emission. The interface between the nanometer material and the metal of the functionalized needle tip has higher interface resistance and lower mechanical strength, and the practical application of the nanometer material and the metal is limited to a great extent. Our previous patent documents report a novel carbon nanocone functionalized needle tip and a method for preparing the same[5]And adhering the carbon nanocone to the front end of the metal needle tip substrate by using a micro-nano operation instrument, and then further heating by applying current or irradiating by laser and the like to obtain covalent bond interface connection between the carbon nanocone and the metal needle tip substrate. The carbon nano-cone functionalized needle tip prepared by the method has excellent interface performance, small interface contact resistance and high mechanical strength. The stable and controllable structure of the carbon nano-cone functionalized needle tip provides a foundation for the practical application of the carbon nano-cone functionalized needle tip in the fields of electron emission sources and the like.
For electron emission applications, the work function of the emission material is a very important parameter affecting the electron emission performance, and the lower work function can effectively improve the current density and monochromaticity of the emission beam. The work function is mainly controlled by the material type, surface morphology, crystal orientation and other structural factors. Swanson et al first modified a thin film of low work function zirconia on a single crystal W [100 ]]On the face[6]The work function is reduced from 4.5eV to 2.5eV, so that the emission beam size is remarkably increased. Film of titanium oxide[7]Emission cathode modified with yttrium oxide film[8]Its lower surface work function is also theoretically predicted to have an effect on electron emission. Narasimha et al also recently reported that the work function of the Au material modified by adamantane is reduced from 5.1eV to 1.6eV, which brings about the remarkable improvement of the electron emission performance[9]。
As described above, the carbon nanocone functionalized needle tip has a stable and controllable structure. However, the tip of the carbon nanocone is a closed multi-layered graphite structure having a high work function (about 4.8eV)[10]The performance of electron emission is limited to some extent. One work that we have previously reported the preparation of carbon nanocone powder samples with tapered gadolinium oxide filled inside using solvent evaporation[11]However, gadolinium oxide has a high work function and poor conductivity, and cannot be used to prepare a carbon nanocone functionalized tip with a low work function. In comparison, some pure metals, metal carbides, borides, nitrides, and metal fullerene inclusion compounds (EMF), etc., have lower work functions and higher electrical conductivities. So far, the carbon nano cone functionalized needle tip modified by the low work function material has not been reported. On the other hand, there are many reports on the metal compound modified carbon nanotube composite material[12]However, the functionalized needle tip of the carbon nanotube modified by the metal fullerene clathrate compound has not been reported yet.
Reference to the literature
[1]Houdellier,F.,et al.,Development of TEM and SEM high brightness electron guns using cold-field emission from a carbon nanotip.2015.151:p.107-115.
[2]Zhang,H.,et al.,An ultrabright and monochromatic electron point source made of a LaB6 nanowire.Nature Nanotechnology,2016.11(3):p.273-+.
[3]Slattery,A.D.,et al.,Efficient attachment of carbon nanotubes to conventional and high-frequency AFM probes enhanced by electron beam processes.Nanotechnology,2013.24(23).
[4]de Jonge,N.and J.M.Bonard,Carbon nanotube electron sources and applications.Philosophical Transactions of the Royal Society a-Mathematical Physical and Engineering Sciences,2004.362(1823):p.2239-2266.
[5] Xu jian, zhao yuliang, a cone-shaped nanometer carbon material functionalized needle tip and a preparation method thereof, Chinese patent No. ZL 201610091160.0; a popular Nano-carbon Material functionalized Needle and Preparation Method for, US patent No. US10823758B2.
[6]Swanson,L.W.and G.A.Schwind,Review of ZrO/W Schottky Cathode,in Handbook of Charged Particle Optics,J.Orloff,Editor.2009,CRC Press.p.1.
[7]Hirose,K.and M.Tsukada,FIRST-PRINCIPLES CALCULATION OF THE ELECTRONIC-STRUCTURE FOR A BIELECTRODE JUNCTION SYSTEM UNDER STRONG-FIELD AND CURRENT.Physical Review B,1995.51(8):p.5278-5290.
[8]Kobayashi,K.,First-principles study of the surface electronic structures of transition metal carbides.Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications&Review Papers,2000.39(7B):p.4311-4314.
[9]Narasimha,K.T.,et al.,Ultralow effective work function surfaces using diamondoid monolayers.Nature Nanotechnology,2016.11:p.267-272.
[10]Zhu,F.,et al.,Heating graphene to incandescence and the measurement of its work function by the thermionic emission method.Nano Research,2014.7(4):p.553-560.
[11]Xu,L.L.,et al.,Investigation of the crystallization behaviors in asub-micron space using carbon nanocones.RSC Adv.,2017.7:p.50688.
[12]Gautam,U.K.,et al.,Recent developments in inorganicallyfilled carbon nanotubes:successesand challenges.Sci.Technol.Adv.Mater.,2010.11:p.054501.
Disclosure of Invention
The invention aims to provide a carbon nano material functionalized needle tip modified by a low-work-function material, which has a lower electron emission potential barrier, can effectively reduce the electric field intensity required by electron emission, and improve the emission current and the emission efficiency; the invention also aims to provide a preparation method of the carbon nano material functionalized needle tip modified by the low work function material.
Specifically, the invention provides the following technical scheme:
the invention provides a carbon nano material functionalized needle tip modified by a low work function material, which is formed by combining a carbon nano material with a needle tip material through a covalent bond; a low work function material is modified inside or on the outer surface of the carbon nano material;
wherein, the needle point is made of metal and is selected from one or more of tungsten, iron, cobalt, nickel and titanium; the carbon nano material is a carbon nano cone or a carbon nano tube; the low work function material is one or more selected from metal, metal carbide, metal oxide, boride, nitride and metal fullerene inclusion compound.
The invention discovers that the carbon nano material functionalized needle tip formed by combining the carbon nano material with the needle tip material through the covalent bond has a more stable needle tip structure and a lower electron emission potential barrier compared with other carbon nano material needle tips in the prior art by modifying the low work function material in the interior or the outer surface of the carbon nano material, and can effectively reduce the electric field intensity required by electron emission and improve the emission current and the emission efficiency.
Preferably, the tip of the carbon nanomaterial coincides with the orientation of the metal tip.
Preferably, the carbon nanocone is a tapered carbon nanomaterial composed of a layered graphite structure.
Preferably, the carbon nanotube is a tubular carbon nanomaterial composed of a layered graphite structure.
Preferably, the low work function material is selected from Ba, Ca, Yb, WC, HfC, NbC, TaC, Ni3C、LaB6、CeB6、TiN、GaN、Sr3N2、Ca@C82、Lu2C2@C82、Sc3N@C80、BaO、ZnO、ZrO2One or more of (a).
In the invention, the work function of the needle point can be effectively reduced by selecting a proper low work function material for modification. Specifically, metals such as Ba, Ca, Yb, and the like have low work functions and are easily deposited on a needle tip or a surface of a carbon nanomaterial by an evaporation method; metal carbides and nitrides, e.g. WC, HfC, NbC, TaC, Ni3C、TiN、GaN、Sr3N2The work function of these materials is low, and many studies have been reported to use these materials as electron emission sources (Ishizawa, Y.et al., appl.Surf.Sci.,1993,67, 36; Tang, S.et al., Nanoscale,2020,12, 16770; Wang, Y.Q.et al., appl.Surf.Sci.,2013,285,115); LaB6And CeB6Thermal emission electron sources used on commercial electron microscopes, also due to their lower work function; certain low work function metal oxides, e.g. BaO, ZrO2ZnO, etc., are also used in large quantities in thermal emissive cathode materials (Yamamoto, s.rep.prog.phys.,2006,69, 181). Under the preferred conditions of the invention, the low work function material forms nanoscale films or particles in the carbon nanocones or the outer surfaces of the carbon nanotubes, so that the work function of the carbon nanomaterials can be effectively reduced, and the functionalized needlepoint of the obtained carbon nanomaterials has a lower work function.
On the other hand, in the above-mentioned low work function materials, metals, metal carbides, metal nitrides, and metal borides are unstable under the working conditions of electron emission, and the high temperature (generally higher than 1000 ℃) and high energy ion bombardment of the electron emission may cause oxidation and structural destruction of the above-mentioned low work function materials. Metal oxides are relatively more stable, but can sublime at high temperatures causing losses, and the low conductivity of the oxide greatly limits the magnitude of its emission current. Under the optimized condition of the invention, the low work function material is positioned in the carbon nano material, and the continuous and closed graphite layer structure of the carbon nano material can effectively prevent the oxidation and the loss of the internal material. Meanwhile, under the optimal conditions, the metal oxide exists in the carbon nano material in the form of nano particles or nano films, and the metal oxide and the carbon nano material form good electrical contact, so that the defect of poor conductivity of the metal oxide can be effectively overcome. Meanwhile, the prepared carbon nano material on the functionalized needle tip is firmly connected with the metal needle tip through a covalent bond interface, the mechanical and electrical properties are excellent, a stable structure is endowed to the functionalized needle tip, and a low work function material is protected.
The metal fullerene clathrate is a compound which wraps metal, metal carbide or nitride molecule clusters in a fullerene carbon cage. Similar to the materials, the low work function molecular cluster in the carbon nano material can also reduce the work function of the carbon nano material, and the carbon nano material can play a better role in protecting and supporting the metal fullerene clathrate compound.
Preferably, the needle tip is in a conventional needle tip shape, and the vertex angle of the tip of the needle tip is 10-70 degrees.
Preferably, the tip of the needle tip is completely covered by a single carbon nanocone, and the tail of the carbon nanocone covers the tip of the needle tip.
Preferably, the tip of the needle tip is modified by a single carbon nanotube cluster or a single carbon nanotube.
The invention also provides a preparation method of the carbon nano material functionalized needle tip modified by the low work function material.
Specifically, the preparation method provided by the invention can be divided into two parallel technical schemes according to the modified part of the low work function material.
As one of the technical proposal:
when a low work function material is modified in the carbon nanomaterial, the preparation method provided by the invention is divided into two operation modes, specifically as follows:
the preparation method comprises the following steps:
(1) modifying a low work function material on the surface of the needle tip;
(2) assembling a carbon nano material to the front end of a needle tip of a surface-modified low-work-function material, and applying current or laser irradiation to form firm interface connection between the carbon nano material and the needle tip;
preferably, in the step (1), the surface of the tip is modified with a low work function material having a thickness of 1 to 100nm by an ion sputtering method, a vapor deposition method, or an electroplating method.
In a specific embodiment, a needle tip made of a suitable material is selected and fixed on a sample table of equipment by an evaporation method, and a target material or powder made of a low work function material is installed in a vacuum cavity of the equipment, is excited by a high-energy electron beam under a suitable working condition, enters a gas phase and is deposited on the surface of the needle tip.
Preferably, in the step (2), depositing the carbon nano material on the silicon wafer substrate by using a film spinning instrument; adhering carbon nano material to the tip of the needle point of the surface-modified low-work-function material, contacting the needle body with another metal body, applying voltage between the metal body and the needle body, enabling current to pass through the needle body, and heating the tip part of the needle and combining with the adhered carbon nano material.
Further, the metal body has a top end in a spherical or flat shape; the distance between the contact position of the metal body and the needle body and the top end of the needle point is 0.2-100 mu m; the metal body and the needle tip are made of tungsten; the current passing through the needle body is 0.04-4A.
The preparation method comprises the following steps:
(1) filling a low work function material in the carbon nano material;
(2) assembling the carbon nano material filled with the low work function material into the front end of the needle tip, and applying current or laser irradiation to form firm interface connection between the two.
Preferably, in the step (1), the low work function material is filled in the carbon nanomaterial by a vacuum vapor filling method, a melt phase filling method or a solution filling method; the specific operation is as follows:
placing carbon nano material powder into a reactor, mixing and contacting with steam, molten liquid or solution of a low work function material compound, maintaining the reaction for 2-36 h, washing the low work function material which is not filled into the carbon nano material by using a solvent, carrying out suction filtration, and drying.
Preferably, in the step (2), depositing the carbon nanomaterial filled with the low work function material inside on the silicon wafer substrate by using a spin coater; adhering carbon nanometer material to the tip of the needle tip, contacting the needle body with another metal body, applying voltage between the metal body and the needle body, passing current through the needle body, and heating the tip of the needle to combine with the adhered carbon nanometer material.
Further, the metal body has a top end in a spherical or flat shape; the distance between the contact position of the metal body and the needle body and the top end of the needle point is 0.2-100 mu m; the metal body and the needle tip are made of tungsten; the current passing through the needle body is 0.04-4A.
As a second technical solution:
when the outer surface of the carbon nano material functionalized needle tip is modified with a low work function material, the preparation method comprises the following steps:
(1) assembling the carbon nano material to the front end of the needle tip, and applying current or laser irradiation to form firm interface connection between the carbon nano material and the needle tip to obtain the carbon nano material functionalized needle tip;
(2) and modifying a low work function material on the outer surface of the carbon nano material functionalized needle tip.
Preferably, in the step (1), depositing the carbon nano material on the silicon wafer substrate by using a film spinning instrument; adhering a carbon nano material to the tip of the needle point, contacting the needle body with another metal body, applying a voltage between the metal body and the needle body, enabling a current to pass through the needle body, and heating the tip part of the needle and combining with the adhered carbon nano material;
wherein the metal body has a spherical or platform-shaped top end; the distance between the contact position of the metal body and the needle body and the top end of the needle point is 0.2-100 mu m; the metal body and the needle tip are made of tungsten; the current passing through the needle body is 0.04-4A.
Preferably, in the step (2), the outer surface of the carbon nanomaterial functionalized needle tip is modified with a low work function material with a thickness of 1-100 nm by an ion sputtering method, an evaporation method, a vapor deposition method or an electroplating method.
In a specific embodiment, a needle tip made of a suitable material is selected and fixed on a sample table of equipment by an evaporation method, and a target material or powder made of a low work function material is arranged in a vacuum cavity of the equipment, is excited by a high-energy electron beam under a suitable working condition, enters a gas phase and is deposited on the outer surface of the functionalized needle tip made of the carbon nano material.
The invention has the beneficial effects that:
the carbon nano material functionalized needle tip modified by the low work function material provided by the invention has a lower work function than that of a carbon nano material and a more stable structure than that of the low work function material, and can effectively improve the electron emission performance, stability and service life of the needle tip.
Drawings
FIG. 1(a) is a photograph of a micromanipulation system mounted in a scanning electron microscope as a real object, 1 and 2 are micromanipulation arms, and 3 is a sample stage. Fig. 1(b) is a scanning electron microscope photograph of a carbon nanocone functionalized nanoprobe tip prepared by heating a metal tip # 2 by an instantaneous current after a metal body # 1 having a spherical structure at the top end contacts the metal tip # 2.
Fig. 2 is a transmission electron microscope image and a corresponding energy spectrum of a low work function metal Ba-modified carbon nanocone functionalized needle tip prepared after a Ba thin film is deposited at the tip of a metal tungsten needle tip.
FIG. 3 is a transmission electron microscope image and corresponding energy spectrum of a low work function metallic oxide ZnO modified carbon nanocone functionalized needle tip prepared after depositing a ZnO film on the tip of a metal tungsten needle.
FIG. 4 is a transmission electron microscope image and a corresponding energy spectrum of a carbon nanocone functionalized needle tip modified by a low work function metal boride LaB6 prepared after a LaB6 film is deposited on a metal tungsten needle tip.
FIG. 5 is a transmission electron microscope image and a corresponding energy spectrum of a carbon nanocone functionalized needle tip modified by a low work function metal carbide Ni3C prepared after a Ni3C film is deposited at the tip end of a metal tungsten needle.
FIG. 6 is a transmission electron microscope image and corresponding energy spectrum of a TaC-modified carbon nanocone functionalized needle tip prepared after a TaC film is deposited on the tip of a metal tungsten needle.
FIG. 7 is a transmission electron microscope image and corresponding energy spectrum of a low work function metal carbide WC modified carbon nanocone functionalized needle tip prepared after a C film is deposited by an electron beam at the end of a metal tungsten needle tip.
FIG. 8 is a transmission electron microscope image and corresponding energy spectrum of a low work function metal nitride TiN modified carbon nanocone functionalized needle tip prepared after a TiN film is deposited on the tip end of a metal tungsten needle.
FIG. 9 is a transmission electron microscope image of a carbon nanocone functionalized needle tip coated with a low work function metallic oxide ZnO film on the outer surface and a corresponding energy spectrum.
Fig. 10(a, b) is a transmission electron micrograph of a carbon nanocone tip filled with scandium acetate by a solution filling method and (c, d) is a transmission electron micrograph of a corresponding scandia filled carbon nanocone functionalized nanocone tip.
Detailed Description
The invention is further illustrated below with reference to specific examples, in which it is noted that: the following examples are intended to illustrate specific embodiments of the present invention and are not intended to limit the scope of the claims.
The micromanipulator used in the examples was manufactured by Kleindiik Nanotechnik, a scanning microscope was FEIQuanta 200FEG, and a transmission electron microscope was FEI F20.
The film throwing instrument is a KW-4A type film throwing instrument produced by the institute of electronics of Chinese academy of sciences.
The magnetron sputtering coating system is Lab-18.
The electron beam evaporation coating system is OHMIKER-50B.
The heating and stirring device is MS-H-PRO.
The digital display infrared baking lamp is LP 23030-B.
Example 1
In this example, a metal W tip was coated with a 5nm thick Ba thin film (Ba target purity: 99.99%) on the surface by an electron beam evaporation coating method, No. 2. The method comprises the following steps of dispersing carbon nanocone materials in an o-dichlorobenzene solvent through ultrasound, depositing obtained dispersion liquid on a silicon wafer substrate through a film throwing instrument, then installing the silicon wafer substrate on a sample table 3 of a scanning electron microscope, respectively installing tungsten needle points # 1 and #2 on needle tubes at the front ends of No. 1 and No. 2 micro-operation arms in the figure 1, and controlling the micro-operation arms to realize three-dimensional space movement of the tungsten needle points in a sample chamber of the scanning electron microscope.
The tungsten tip # 1 was moved so that the tip lightly contacted the tip of the tungsten probe # 2 at a position of 50 μm to form a via, and the tip of the tungsten probe # 1 was immediately melted into a spherical structure of 2 μm by applying a bias of 50V. And then controlling the #2 tungsten probe through a micro-operation arm, enabling the needle tip to slowly approach the carbon nanocone deposited on the substrate, inserting the tail part of the carbon nanocone, and lifting the needle tip upwards to enable the carbon nanocone to slowly leave the substrate. The #1 molten tungsten metal sphere was brought into contact with the #2 metal tip side by a micro-manipulator arm, the contact point being 2 μm from the tip. Applying a voltage across the two tungsten tips produced a current of 3A with an energization duration of 0.25 ms.
Fig. 2 is a Transmission Electron Microscope (TEM) photograph of the present embodiment, and the high resolution image shows that the prepared functionalized tip has a carbon nanocone, a Ba plating layer, and a W tip from the outside to the inside structure, and the carbon nanocone structure is not changed when the tungsten tip is melted, which indirectly illustrates the structural stability; the presence of the fill Ba was confirmed by X-ray energy spectroscopy (EDX) analysis.
Example 2
In this example, a ZnO thin film (purity of magnetron sputtering ZnO target: 99.99%) having a thickness of 5nm was deposited on the surface of a metallic W tip by a magnetron sputtering deposition method, and the tip was numbered # 2. The method comprises the following steps of dispersing carbon nanocone materials in an o-dichlorobenzene solvent through ultrasound, depositing obtained dispersion liquid on a silicon wafer substrate through a film throwing instrument, then installing the silicon wafer substrate on a sample table 3 of a scanning electron microscope, respectively installing tungsten needle points # 1 and #2 on needle tubes at the front ends of No. 1 and No. 2 micro-operation arms in the figure 1, and controlling the micro-operation arms to realize three-dimensional space movement of the tungsten needle points in a sample chamber of the scanning electron microscope.
The tungsten tip # 1 was moved so that the tip lightly contacted the tip of the tungsten probe # 2 at a position of 50 μm to form a via, and the tip of the tungsten probe # 1 was immediately melted into a spherical structure of 2 μm by applying a bias of 50V. And then controlling the #2 tungsten probe through a micro-operation arm, enabling the needle tip to slowly approach the carbon nanocone deposited on the substrate, inserting the tail part of the carbon nanocone, and lifting the needle tip upwards to enable the carbon nanocone to slowly leave the substrate. The #1 molten tungsten metal sphere was brought into contact with the #2 metal tip side by a micro-manipulator arm, the contact point being 2 μm from the tip. A voltage was applied to the two tungsten tips to generate a current of 3A, with an energization duration of 0.2 ms.
Fig. 3 is a TEM photograph of the present embodiment, and the high resolution image shows that the prepared functionalized tip has a carbon nanocone, ZnO nanoparticles, and a W tip from the outside to the inside, and the carbon nanocone structure is not changed when the tip of the tungsten tip is melted, which indirectly illustrates the stability of the structure; the X-ray energy spectrum (EDX) analysis confirmed the presence of the filler ZnO. The ZnO obtained in this example was present on the inner surface of the carbon nanocone in the form of nanoparticles, and was in good contact with the carbon nanocone.
Example 3
In this example, a 5nm thick LaB6 film (LaB6 target purity: 99.99%) was deposited on the surface of a metal W tip by electron beam evaporation coating (No. 2). The method comprises the following steps of dispersing carbon nanocone materials in an o-dichlorobenzene solvent through ultrasound, depositing obtained dispersion liquid on a silicon wafer substrate through a film throwing instrument, then installing the silicon wafer substrate on a sample table 3 of a scanning electron microscope, respectively installing tungsten needle points # 1 and #2 on needle tubes at the front ends of No. 1 and No. 2 micro-operation arms in the figure 1, and controlling the micro-operation arms to realize three-dimensional space movement of the tungsten needle points in a sample chamber of the scanning electron microscope.
The tungsten tip # 1 was moved so that the tip lightly contacted the tip of the tungsten probe # 2 at a position of 50 μm to form a via, and the tip of the tungsten probe # 1 was immediately melted into a spherical structure of 2 μm by applying a bias of 50V. And then controlling the #2 tungsten probe through a micro-operation arm, enabling the needle tip to slowly approach the carbon nanocone deposited on the substrate, inserting the tail part of the carbon nanocone, and lifting the needle tip upwards to enable the carbon nanocone to slowly leave the substrate. The #1 molten tungsten metal sphere was brought into contact with the #2 metal tip side by a micro-manipulator arm, the contact point being 2 μm from the tip. Applying a voltage across the two tungsten tips produced a current of 3A with an energization duration of 0.25 ms.
FIG. 4 is a TEM photograph of the present example, wherein the high resolution image shows that the prepared functionalized nanoprobe has a carbon nanocone, a LaB6 and a W tip from the outside to the inside; the presence of the filler LaB6 was confirmed by X-ray energy spectroscopy (EDX) analysis.
Example 4
In this example, a tip of a metal W was coated with a 5 nm-thick nickel carbide thin film (purity of a magnetron sputtering nickel carbide target: 99.99%) by a magnetron sputtering coating method, and numbered # 2. The method comprises the following steps of dispersing carbon nanocone materials in an o-dichlorobenzene solvent through ultrasound, depositing obtained dispersion liquid on a silicon wafer substrate through a film throwing instrument, then installing the silicon wafer substrate on a sample table 3 of a scanning electron microscope, respectively installing tungsten needle points # 1 and #2 on needle tubes at the front ends of No. 1 and No. 2 micro-operation arms in the figure 1, and controlling the micro-operation arms to realize three-dimensional space movement of the tungsten needle points in a sample chamber of the scanning electron microscope.
The tungsten tip # 1 was moved so that the tip lightly contacted the tip of the tungsten probe # 2 at a position of 50 μm to form a via, and the tip of the tungsten probe # 1 was immediately melted into a spherical structure of 2 μm by applying a bias of 50V. And then controlling the #2 tungsten probe through a micro-operation arm, enabling the needle tip to slowly approach the carbon nanocone deposited on the substrate, inserting the tail part of the carbon nanocone, and lifting the needle tip upwards to enable the carbon nanocone to slowly leave the substrate. The #1 molten tungsten metal sphere was brought into contact with the #2 metal tip side by a micro-manipulator arm, the contact point being 2 μm from the tip. Applying a voltage across the two tungsten tips produced a current of 3A with an energization duration of 0.25 ms.
FIG. 5 is a TEM photograph of the present example, wherein the high resolution image shows that the prepared functionalized nanoprobe has a carbon nanopyramid, nickel carbide and W tip from the outside to the inside; x-ray energy spectrum (EDX) analysis confirmed the presence of the filler nickel carbide.
Example 5
In this example, a TaC thin film (purity of a magnetron sputtering TaC target: 99.99%) having a thickness of 5nm was formed on the surface of a metal W tip by an electron beam evaporation coating method, and numbered # 2. The method comprises the following steps of dispersing carbon nanocone materials in an o-dichlorobenzene solvent through ultrasound, depositing obtained dispersion liquid on a silicon wafer substrate through a film throwing instrument, then installing the silicon wafer substrate on a sample table 3 of a scanning electron microscope, respectively installing tungsten needle points # 1 and #2 on needle tubes at the front ends of No. 1 and No. 2 micro-operation arms in the figure 1, and controlling the micro-operation arms to realize three-dimensional space movement of the tungsten needle points in a sample chamber of the scanning electron microscope.
The tungsten tip # 1 was moved so that the tip lightly contacted the tip of the tungsten probe # 2 at a position of 50 μm to form a via, and the tip of the tungsten probe # 1 was immediately melted into a spherical structure of 2 μm by applying a bias of 50V. And then controlling the #2 tungsten probe through a micro-operation arm, enabling the needle tip to slowly approach the carbon nanocone deposited on the substrate, inserting the tail part of the carbon nanocone, and lifting the needle tip upwards to enable the carbon nanocone to slowly leave the substrate. The #1 molten tungsten metal sphere was brought into contact with the #2 metal tip side by a micro-manipulator arm, the contact point being 2 μm from the tip. Applying a voltage across the two tungsten tips produced a current of 3A with an energization duration of 0.25 ms.
FIG. 6 is a TEM photograph of the present example, wherein the high resolution image shows that the prepared functionalized nanoprobe has a carbon nanocone, TaC and W tip from the outside to the inside; the results of the X-ray energy spectrum (EDX) analysis confirm the presence of the filler TaC. The TaC obtained in this example was present as nanoparticles on the inner surface of the carbon nanocone, and was in good contact with the carbon nanocone.
Example 6
In this example, a metal W tip was subjected to electron beam induced carbon deposition under a scanning electron microscope to deposit carbon 5nm thick on the surface, No. # 2. The method comprises the following steps of dispersing carbon nanocone materials in an o-dichlorobenzene solvent through ultrasound, depositing obtained dispersion liquid on a silicon wafer substrate through a film throwing instrument, then installing the silicon wafer substrate on a sample table 3 of a scanning electron microscope, respectively installing tungsten needle points # 1 and #2 on needle tubes at the front ends of No. 1 and No. 2 micro-operation arms in the figure 1, and controlling the micro-operation arms to realize three-dimensional space movement of the tungsten needle points in a sample chamber of the scanning electron microscope.
The tungsten tip # 1 was moved so that the tip lightly contacted the tip of the tungsten probe # 2 at a position of 50 μm to form a via, and the tip of the tungsten probe # 1 was immediately melted into a spherical structure of 2 μm by applying a bias of 50V. And then controlling the #2 tungsten probe through a micro-operation arm, enabling the needle tip to slowly approach the carbon nanocone deposited on the substrate, inserting the tail part of the carbon nanocone, and lifting the needle tip upwards to enable the carbon nanocone to slowly leave the substrate. The #1 molten tungsten metal sphere was brought into contact with the #2 metal tip side by a micro-manipulator arm, the contact point being 2 μm from the tip. Applying a voltage across the two tungsten tips produced a current of 3A with an energization duration of 0.25 ms.
FIG. 7 is a TEM photograph of the present example, and the high resolution image shows the prepared tungsten carbide-modified carbon nanocone functionalized nanoprobe; the X-ray energy spectrum (EDX) analysis confirmed the presence of W and C.
Example 7
In this example, a tip of a metal W was coated with a 5nm thick TiN thin film (purity of a magnetron sputtering TiN target: 99.99%) by a magnetron sputtering coating method, No. 2. The method comprises the following steps of dispersing carbon nanocone materials in an o-dichlorobenzene solvent through ultrasound, depositing obtained dispersion liquid on a silicon wafer substrate through a film throwing instrument, then installing the silicon wafer substrate on a sample table 3 of a scanning electron microscope, respectively installing tungsten needle points # 1 and #2 on needle tubes at the front ends of No. 1 and No. 2 micro-operation arms in the figure 1, and controlling the micro-operation arms to realize three-dimensional space movement of the tungsten needle points in a sample chamber of the scanning electron microscope.
The tungsten tip # 1 was moved so that the tip lightly contacted the tip of the tungsten probe # 2 at a position of 50 μm to form a via, and the tip of the tungsten probe # 1 was immediately melted into a spherical structure of 2 μm by applying a bias of 50V. And then controlling the #2 tungsten probe through a micro-operation arm, enabling the needle tip to slowly approach the carbon nanocone deposited on the substrate, inserting the tail part of the carbon nanocone, and lifting the needle tip upwards to enable the carbon nanocone to slowly leave the substrate. The #1 molten tungsten metal sphere was brought into contact with the #2 metal tip side by a micro-manipulator arm, the contact point being 2 μm from the tip. Applying a voltage across the two tungsten tips produced a current of 3A with an energization duration of 0.25 ms.
FIG. 8 is a transmission TEM photograph of the present embodiment, and the high resolution image shows that the prepared functionalized nanoprobe has a carbon nanocone, TiN, W tip from the outside to the inside structure; the X-ray energy spectrum (EDX) analysis confirmed the presence of the filler TiN. The TiN obtained in this example was present as a thin film on the inner surface of the carbon nanocone, and was in good contact with the carbon nanocone.
Example 8
In this embodiment, a carbon nanocone material is ultrasonically dispersed in an o-dichlorobenzene solvent, the obtained dispersion is deposited on a silicon wafer substrate by using a film throwing instrument, then the silicon wafer substrate is mounted on a sample stage 3 of a scanning electron microscope, tungsten tips # 1 and #2 are respectively mounted on needle tubes at the front ends of No. 1 and No. 2 micro-operation arms in the figure 1, and the tungsten tips are controlled to move in a three-dimensional space in a sample chamber of the scanning electron microscope.
The tungsten tip # 1 was moved so that the tip lightly contacted the tip of the tungsten probe # 2 at a position of 50 μm to form a via, and the tip of the tungsten probe # 1 was immediately melted into a spherical structure of 2 μm by applying a bias of 50V. And then controlling the #2 tungsten probe through a micro-operation arm, enabling the needle tip to slowly approach the carbon nanocone deposited on the substrate, inserting the tail part of the carbon nanocone, and lifting the needle tip upwards to enable the carbon nanocone to slowly leave the substrate. The #1 molten tungsten metal sphere was brought into contact with the #2 metal tip side by a micro-manipulator arm, the contact point being 2 μm from the tip. And applying voltage to the two tungsten needle points to generate 3A current, wherein the electrifying duration is 0.25ms, and thus the carbon nano-cone functionalized tungsten needle point is obtained.
The prepared # 2 carbon nanocone functionalized tungsten needle tip is taken out and fixed on a sample stage of a magnetron sputtering device, and a ZnO film with the thickness of 5nm is plated on the surface (the purity of the magnetron sputtering ZnO target: 99.99%). Fig. 9 is a TEM photograph of the present example, and a high resolution image shows that the prepared functionalized nanoprobe has a ZnO thin film, a carbon nanocone, and a W tip in sequence from outside to inside, and the presence of ZnO is confirmed by the X-ray energy spectrum (EDX) analysis result.
Example 9
Taking a 20mL small sample bottle, firstly adding 25mg of scandium acetate, then adding 10mL of ethylene glycol, and carrying out ultrasonic treatment for 10min to uniformly mix the medicines; and (3) putting the magneton into the small reagent bottle, slightly covering the cover, putting the small reagent bottle on a heating stirrer, and setting the heating time for 30min, the heating temperature for 100 ℃, and the stirring speed for 500rpm to completely dissolve scandium acetate. Weighing 2mg of carbon nanocone, adding the carbon nanocone into the solution, lightly covering the small reagent bottle cap, placing the small reagent bottle cap on a heating stirrer, setting the heating time to be 18h, the heating temperature to be 100 ℃, and the stirring speed to be 500rpm, so that scandium acetate is filled into the tip of the carbon nanocone; after the heating and stirring are finished, cooling the black mixture to room temperature, filtering the black mixture by using a hydrophilic filter membrane with the aperture of 1 mu m, and baking the filtered sample and the filter membrane for 20 hours under an infrared lamp, wherein the baking temperature is set to 80 ℃. The sample was scraped off the filter, taken a little less than absolute ethanol, and ultrasonically dispersed, and then dropped on a micro-grid copper mesh for observation by a Transmission Electron Microscope (TEM), and the transmission electron microscope image of the filled carbon nanocone is shown in fig. 10(a, b).
Dispersing the filled carbon nanocones in an o-dichlorobenzene solvent by ultrasonic, depositing the obtained dispersion liquid on a silicon wafer substrate by using a film throwing instrument, then installing the silicon wafer substrate on a scanning electron microscope sample table of a scanning electron microscope, installing tungsten probes # 1 and #2 on needle tubes at the front ends of No. 1 and No. 2 micro-operation arms respectively in the same way as the embodiment, and applying current to prepare the carbon nanocone functionalized nanocone tip filled with scandium oxide while decomposing scandium acetate to generate scandium oxide by controlling the micro-operation instrument to contact and adhere to one carbon nanocone filled with scandium acetate, as shown in fig. 10(c, d). The scandium oxide obtained in this example exists on the inner surface of the carbon nanocone in the form of nanoparticles or a thin film, and is in good contact with the carbon nanocone.
Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (10)
1. A carbon nano material functionalized needle tip modified by a low work function material is characterized in that the carbon nano material is combined with the material of the needle tip through a covalent bond; a low work function material is modified inside or on the outer surface of the carbon nano material;
wherein, the needle point is made of metal and is selected from one or more of tungsten, iron, cobalt, nickel and titanium; the carbon nano material is a carbon nano cone or a carbon nano tube; the low work function material is one or more selected from metal, metal carbide, metal oxide, boride, nitride and metal fullerene inclusion compound.
2. The low work function material modified carbon nanomaterial functionalized needle tip of claim 1, wherein the tip of the carbon nanomaterial is in accordance with the orientation of the metal needle tip;
and/or the carbon nanocones are tapered carbon nanomaterials consisting of a layered graphite structure;
and/or the carbon nano tube is a tubular carbon nano material consisting of a layered graphite structure;
and/or the low work function material is selected from Ba, Ca, Yb, WC, HfC, NbC, TaC and Ni3C、LaB6、CeB6、TiN、GaN、Sr3N2、Ca@C82、Lu2C2@C82、Sc3N@C80、BaO、ZnO、ZrO2One or more of;
and/or the needle point is in a conventional needle point shape, and the vertex angle of the tip end of the needle point is 10-70 degrees.
3. The method for preparing the carbon nano-material functionalized needle tip modified by the low work function material as claimed in claim 1 or 2, wherein when the low work function material is modified in the carbon nano-material, the method comprises the following steps:
(1) modifying a low work function material on the surface of the needle tip;
(2) assembling a carbon nano material to the front end of a needle tip of a surface-modified low-work-function material, and applying current or laser irradiation to form firm interface connection between the carbon nano material and the needle tip;
or, comprising the following steps:
(1) filling a low work function material in the carbon nano material;
(2) assembling the carbon nano material filled with the low work function material into the front end of the needle tip, and applying current or laser irradiation to form firm interface connection between the two.
4. The preparation method of claim 3, wherein the surface of the needle tip is modified with a low work function material with a thickness of 1-100 nm by an ion sputtering method, an evaporation method, a vapor deposition method or an electroplating method.
5. The production method according to claim 3, characterized in that a low work function material is filled inside the carbon nanomaterial by a vacuum vapor filling method, a melt phase filling method, or a solution filling method; the specific operation is as follows:
placing carbon nano material powder into a reactor, mixing and contacting with steam, molten liquid or solution of a low work function material compound, maintaining the reaction for 2-36 h, washing the low work function material which is not filled into the carbon nano material by using a solvent, carrying out suction filtration, and drying.
6. The method of claim 3, wherein the carbon nanomaterial is deposited on the silicon wafer substrate by a spin coater; adhering carbon nano material to the tip of the needle point of the surface-modified low-work-function material, contacting the needle body with another metal body, applying voltage between the metal body and the needle body, enabling current to pass through the needle body, and heating the tip part of the needle and combining with the adhered carbon nano material.
7. The preparation method according to claim 3, characterized in that a carbon nanomaterial filled with a low work function material inside is deposited on a silicon wafer substrate by a spin coater; adhering carbon nanometer material to the tip of the needle tip, contacting the needle body with another metal body, applying voltage between the metal body and the needle body, passing current through the needle body, and heating the tip of the needle to combine with the adhered carbon nanometer material.
8. The production method according to claim 6 or 7, wherein the metal body has a round or flat top end; the distance between the contact position of the metal body and the needle body and the top end of the needle point is 0.2-100 mu m; the metal body and the needle tip are made of tungsten; the current passing through the needle body is 0.04-4A.
9. The method for preparing the carbon nanomaterial functionalized needle tip modified by the low work function material as claimed in claim 1 or 2, wherein when the low work function material is modified on the outer surface of the carbon nanomaterial functionalized needle tip, the method comprises the following steps:
(1) assembling the carbon nano material to the front end of the needle tip, and applying current or laser irradiation to form firm interface connection between the carbon nano material and the needle tip to obtain the carbon nano material functionalized needle tip;
(2) and modifying a low work function material on the outer surface of the carbon nano material functionalized needle tip.
10. The method according to claim 9, wherein in the step (1), the carbon nanomaterial is deposited on the silicon wafer substrate by a spin coater; adhering a carbon nano material to the tip of the needle point, contacting the needle body with another metal body, applying a voltage between the metal body and the needle body, enabling a current to pass through the needle body, and heating the tip part of the needle and combining with the adhered carbon nano material;
wherein the metal body has a spherical or platform-shaped top end; the distance between the contact position of the metal body and the needle body and the top end of the needle point is 0.2-100 mu m; the metal body and the needle tip are made of tungsten; the current passing through the needle body is 0.04-4A;
and/or in the step (2), modifying the outer surface of the carbon nano material functionalized needle tip with a low work function material with the thickness of 1-100 nm by adopting an ion sputtering method, an evaporation method, a vapor deposition method or an electroplating method.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110328379.9A CN113223912B (en) | 2021-03-26 | 2021-03-26 | Low work function material modified carbon nano material functionalized needle tip and preparation method thereof |
| EP21187464.9A EP4064321A1 (en) | 2021-03-26 | 2021-07-23 | Carbon nanomaterial functionalized needle tip modified with low work function material and preparation method thereof |
| US17/444,017 US20220308087A1 (en) | 2021-03-26 | 2021-07-29 | Carbon nanomaterial functionalized needle tip modified with low work function material and preparation method thereof |
| JP2021131588A JP7206337B2 (en) | 2021-03-26 | 2021-08-12 | Needle tip functionalized with carbon nanomaterial modified with low work function material, and method for manufacturing same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110328379.9A CN113223912B (en) | 2021-03-26 | 2021-03-26 | Low work function material modified carbon nano material functionalized needle tip and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113223912A true CN113223912A (en) | 2021-08-06 |
| CN113223912B CN113223912B (en) | 2023-12-26 |
Family
ID=77084263
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110328379.9A Active CN113223912B (en) | 2021-03-26 | 2021-03-26 | Low work function material modified carbon nano material functionalized needle tip and preparation method thereof |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US20220308087A1 (en) |
| EP (1) | EP4064321A1 (en) |
| JP (1) | JP7206337B2 (en) |
| CN (1) | CN113223912B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114284120A (en) * | 2021-12-27 | 2022-04-05 | 广东粤港澳大湾区国家纳米科技创新研究院 | Modified carbon nanocone functionalized needle tip and preparation method thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11848169B1 (en) * | 2023-01-21 | 2023-12-19 | Dazhi Chen | Field-emission type electron source and charged particle beam device using the same |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102530917A (en) * | 2012-01-09 | 2012-07-04 | 中国科学院金属研究所 | Method for preparing carbon nanotube structure with sharp end socket |
| CN105712281A (en) * | 2016-02-18 | 2016-06-29 | 国家纳米科学中心 | Conical nano-carbon material functionalized needle tip and preparation method therefor |
| CN105742139A (en) * | 2016-03-31 | 2016-07-06 | 南京邮电大学 | Composite type field emission negative electrode emission source and preparation method therefor |
| CN107424887A (en) * | 2017-07-07 | 2017-12-01 | 国家纳米科学中心 | Photic thermionic emission source based on low work function composite nano materials and preparation method thereof |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050200261A1 (en) * | 2000-12-08 | 2005-09-15 | Nano-Proprietary, Inc. | Low work function cathode |
| US7735147B2 (en) * | 2005-10-13 | 2010-06-08 | The Regents Of The University Of California | Probe system comprising an electric-field-aligned probe tip and method for fabricating the same |
| JP3982558B2 (en) * | 2006-06-05 | 2007-09-26 | 株式会社日立製作所 | Electron source having carbon nanotubes, electron microscope and electron beam drawing apparatus using the same |
| JP2008297174A (en) * | 2007-06-01 | 2008-12-11 | Mie Univ | Method of manufacturing substrate for growing carbon nanotubes |
| TWI369709B (en) * | 2008-04-25 | 2012-08-01 | Hon Hai Prec Ind Co Ltd | Method of making thermal emission electron source |
| US8070929B2 (en) * | 2008-08-21 | 2011-12-06 | Snu R&Db Foundation | Catalyst particles on a tip |
-
2021
- 2021-03-26 CN CN202110328379.9A patent/CN113223912B/en active Active
- 2021-07-23 EP EP21187464.9A patent/EP4064321A1/en active Pending
- 2021-07-29 US US17/444,017 patent/US20220308087A1/en active Pending
- 2021-08-12 JP JP2021131588A patent/JP7206337B2/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102530917A (en) * | 2012-01-09 | 2012-07-04 | 中国科学院金属研究所 | Method for preparing carbon nanotube structure with sharp end socket |
| CN105712281A (en) * | 2016-02-18 | 2016-06-29 | 国家纳米科学中心 | Conical nano-carbon material functionalized needle tip and preparation method therefor |
| CN105742139A (en) * | 2016-03-31 | 2016-07-06 | 南京邮电大学 | Composite type field emission negative electrode emission source and preparation method therefor |
| CN107424887A (en) * | 2017-07-07 | 2017-12-01 | 国家纳米科学中心 | Photic thermionic emission source based on low work function composite nano materials and preparation method thereof |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114284120A (en) * | 2021-12-27 | 2022-04-05 | 广东粤港澳大湾区国家纳米科技创新研究院 | Modified carbon nanocone functionalized needle tip and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| US20220308087A1 (en) | 2022-09-29 |
| EP4064321A1 (en) | 2022-09-28 |
| JP2022151491A (en) | 2022-10-07 |
| CN113223912B (en) | 2023-12-26 |
| JP7206337B2 (en) | 2023-01-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI359108B (en) | Deposition method for nanostructure materials | |
| US7226663B2 (en) | Method for synthesizing nanoscale structures in defined locations | |
| Green et al. | ZnO-nanoparticle-coated carbon nanotubes demonstrating enhanced electron field-emission properties | |
| CN113223912B (en) | Low work function material modified carbon nano material functionalized needle tip and preparation method thereof | |
| George et al. | Microstructure and field emission characteristics of ZnO nanoneedles grown by physical vapor deposition | |
| US20070014148A1 (en) | Methods and systems for attaching a magnetic nanowire to an object and apparatuses formed therefrom | |
| JP5403284B2 (en) | Nanotube / nanohorn complex and method for producing the same | |
| Kaur et al. | Metal foam-carbon nanotube-reduced graphene oxide hierarchical structures for efficient field emission | |
| Zhao et al. | Field emission enhancement of Au-Si nano-particle-decorated silicon nanowires | |
| CN102109535A (en) | Controllable method for preparing atomic force microscope needlepoint with carbon nano tube | |
| US8308930B2 (en) | Manufacturing carbon nanotube ropes | |
| Jain et al. | Copper nanowire–carbon nanotube hierarchical structure for enhanced field emission | |
| KR20220099104A (en) | Emitter of used for Emitting Electron and Method of the same | |
| JP2006292739A (en) | Method and system for sticking magnetic nano wire to object, and device formed therefrom | |
| Bai et al. | Field emission of individual carbon nanotubes on tungsten tips | |
| JP5245087B2 (en) | Nanocarbon material composite paste and pattern forming method using the same | |
| JP5069486B2 (en) | Thin film type electron emission material, method for manufacturing the same, field emission type device, and field emission type display | |
| JP4210756B2 (en) | Carbon nanotube structure | |
| CN114743847A (en) | Micro-nano level modification method for conductive material | |
| JP2012167140A (en) | Ion gel containing dispersed nanoparticle and method for manufacturing the same | |
| Lai et al. | Field emission properties of tetrapod-shaped ZnO/TiN point light source with semicircle reflecting anode | |
| KR101151353B1 (en) | Fabrication method of needle-shape field emission-type electron emitter and field emission-type electron emitter thereby | |
| EP4159670A1 (en) | Functionalized carbon nanocone tip and preparation method therefor | |
| Wang et al. | Room-temperature synthesis and characterisation of ion-induced iron-carbon nanocomposite fibres | |
| CN1352461A (en) | Ballistic electronic emitting source and its preparing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |